New guy here....this is one forum where I actually may be able to help!
If you want great protection, you need to go to a synthetic sealant. While these offer the best protection, they often give a somewhat sterile or "plasticy" look. As far as synthetic sealants go, I like Poorboy's EX-P (
www.poorboysworld.com). I use Zaino (
www.zainostore.com) on my daily drivers and get several months of protection from it.
Products like NXT contain a great amount of fillers. You will find that it appears that you have removed the swirls and scratches when you have really just filled them with oils and silicone. Afew washes later and the swirls are back. If you really want to remove them, something like Menzerna Intentive Polish or Final Polish II would be great. Poorboy's also has a good swirl removal line. You will have to try some of these out and see what the lighest product you can use that will remove the swirls without making more work for you by marring the clearcoat. All clearcoats vary a bit in hardness. Also, for swirl removal, you would be well served by a dual action polisher like the Porter Cable 7424 or a rotary (Dewalt, Hitachi, etc.) if you are really confident.
Best of luck!
-GT